1. Technical Field
The present application relates to morphological control of powder particles, and more particularly to a powder particle shaping device and method.
2. Related Art
Morphological control of powder particles, being one content of powder engineering, is processing of external surface of powder particles with an intended objective, to achieve a special individual or overall function of the powder particles. Relatively spheroidized powder particles can improve the tap density, filling density, and fluidity of the powder, for example, the spheroidization of cement powder particles can improve the performance of cement, the spheroidization of metal ink particles can increase the light reflection degree, and improve the print quality, and the spheroidized copper powder, graphite, and tin powder exhibit advantages in specific application fields thereof. Shaping of the powder particle is an intermediate step to improve the final performances of some products, and also an auxiliary method for modification processing of the powder particles.
There are many methods for surface shaping or morphological control of the powder, and the conventional mechanical shaping method generally including compacting, rolling, ball milling, and vibration grinding. The compacting includes placing a powder in an annular groove, and compacting the packed powder by rotating a driven round roller about a central axis. The rolling includes dropping agglomerates of power between rollers parallel to each other and having gaps therebetween for pulverization and shaping. Ball milling includes placing a powder and harder and abrasion-tolerant grinding balls mixed at a certain ratio in a rolling drum, and rotating the drum about an axis, so that the grinding balls in the rolling drum rise and fall with the rotation of the drum body, and thus the powder is impacted, and interaction force and mutual friction occur between particles. The vibration grinding is similar to the ball milling, except that a vibration drum body reciprocates along a single direction at a certain frequency, so that the grinding balls impact and grind the powder particles. Recently, a patent issued to Tsinghua University discloses a method and device for spheroidization or morphological control of a powder by high-speed pounding and shearing.
The compacting, rolling, vibration grinding, and ball milling all have disadvantage that the mixture of the processed powder and the grinding media partially contacts air in an effective processing stage, that is, there is “open” or “partial open” situation. In processing of the powder particles, the pressure or impact force is released or partially released. For the relatively “soft” or “hard” powder particles, the absolute strength for processing is limited, and the expected effect and efficiency aredifficult to be achieved. In addition, non-cyclic ball milling and vibration grindingboth have the problem of separation of the milling balls from the ground powder, andthe processing strength varies with the increasing abrasion of the grinding balls, thisincurs uncertainty to the processing process. Moreover, the problems of noise andwaste of energy for driving the equipment and the grinding balls to vibrate or rotateare difficult to overcome. Among the disadvantages, the most serious is the limitedcontrollability of the processing intensity.